I have a pair of Edelbrock 750 carbs that are brand new. I was going to put them on my 330's when I was having trouble with the carbs on them and could not get them rebuilt. I finally found some one and kept the Q-jets on there so that I could save fuel. I want to either build or buy some 502's and get around 450-475hp out of them. Will these carbs be ok? I do not want to be leaning them out, not even close. If I can keep these carbs I would like to, however if not then I will sell or trade them for what ever you guys think I will need.

Jon

I would probably use them, once you dial in the jets, metering rods and springs they should be fine for the moderate power application you are suggesting. The HP500 is only running an 830.

I would not use them on a motor that big. I had one on my stock 502 this summer and seized a piston due to running lean. I had 116 primarys and 113 secondarys in it. The largest jets Edelbrock offers are only one size bigger at 119. While it is a great cruising carb I don't believe it will flow enough fuel to keep the motor alive at WOT. Even the Edelbrock catalog states that you should run the appropriate 850cfm carb for racing and high performance use when using a Performer RPM 2-R intake manifold.

I think I am going to use a Holley 800 next year on my 502. Both Teague and Tommy at Chief Engines recommeded that carb when I called and asked. It is the same carb used on the HP500. It is also priced very good, too. Chief Engines has them for $400.00. Not bad. Sell the Edelbrocks for $200 each and your halfway there.

audio
i'm running edelbrock 750's with 475 hp or better motors and i'm happy with them. 116 jet on primary with 070x037 rod, moved the stock primary metering rods to the secondarys and jetted that to .113. even may be running a little rich now but it's staying that way because i have melted pistons before too. it also has the orange spring stock, but i may change that to yellow.

On my 502 with the oval merlins I took off the choke and both rods plug the two holes run .113 in both and the last rod change was to .068-.047 and run the 5" vacuum spring.The needles and seats .135 and the accelerator pump nozzels are .043 and use the leanest hole on the pump linkage.Plugs seem to be looking good for now.

What intake manifold are you guys using? It sounds like we all run similiar jetting but, I partially seized the #4 piston after running WOT for less than 2 minutes. I heard a tinny, rattling sound and backed off the throttle. That sound worried me so a couple of days later I pulled the plugs and did a compression check. #4 plug was white and down 20 lbs. I then did a leak down test and it was at 50%. Engine is repaired and ready to go again. I am using an Edelbrock Performer RPM, rectangle ports. Could the manifold be the problem?

Macdad Holly 300-42 but rember oval Merlins on mine Did you do a visual of the power valve pistons at WOT ? I also have a vacuum gage in the engine box and do a engine box check at least three times durning the day, at start up, midday and on the run home.maybe over kill but I don't care only takes a second or two. When I worked offshore it was done every hour

"Did you do a visual inspection of the power valve pistons at WOT?" Do you mean the metering rod pistons? I don't know how you would do that. They are under the little covers that hold them in place. I would assume they were opening all the way. I had them out many times when playing with the jetting. They seemed to work freely.

Macdad yes you back out the screws just enough to allow you to move the plates over to the side and you can watch the power valves pistons at any given RPM range most important at WOT they are all the way up .

What is an engine box check and how are you using the vacuum gauge? Do you work on an oil rig or something?